1/**
2 *
3 * GSPCA sub driver for W996[78]CF JPEG USB Dual Mode Camera Chip.
4 *
5 * Copyright (C) 2009 Hans de Goede <hdegoede@redhat.com>
6 *
7 * This module is adapted from the in kernel v4l1 w9968cf driver:
8 *
9 * Copyright (C) 2002-2004 by Luca Risolia <luca.risolia@studio.unibo.it>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 *
25 */
26
27/* Note this is not a stand alone driver, it gets included in ov519.c, this
28   is a bit of a hack, but it needs the driver code for a lot of different
29   ov sensors which is already present in ov519.c (the old v4l1 driver used
30   the ovchipcam framework). When we have the time we really should move
31   the sensor drivers to v4l2 sub drivers, and properly split of this
32   driver from ov519.c */
33
34#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35
36#define W9968CF_I2C_BUS_DELAY    4 /* delay in us for I2C bit r/w operations */
37
38#define Y_QUANTABLE (&sd->jpeg_hdr[JPEG_QT0_OFFSET])
39#define UV_QUANTABLE (&sd->jpeg_hdr[JPEG_QT1_OFFSET])
40
41static const struct v4l2_pix_format w9968cf_vga_mode[] = {
42	{160, 120, V4L2_PIX_FMT_UYVY, V4L2_FIELD_NONE,
43		.bytesperline = 160 * 2,
44		.sizeimage = 160 * 120 * 2,
45		.colorspace = V4L2_COLORSPACE_JPEG},
46	{176, 144, V4L2_PIX_FMT_UYVY, V4L2_FIELD_NONE,
47		.bytesperline = 176 * 2,
48		.sizeimage = 176 * 144 * 2,
49		.colorspace = V4L2_COLORSPACE_JPEG},
50	{320, 240, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
51		.bytesperline = 320 * 2,
52		.sizeimage = 320 * 240 * 2,
53		.colorspace = V4L2_COLORSPACE_JPEG},
54	{352, 288, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
55		.bytesperline = 352 * 2,
56		.sizeimage = 352 * 288 * 2,
57		.colorspace = V4L2_COLORSPACE_JPEG},
58	{640, 480, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
59		.bytesperline = 640 * 2,
60		.sizeimage = 640 * 480 * 2,
61		.colorspace = V4L2_COLORSPACE_JPEG},
62};
63
64static void reg_w(struct sd *sd, u16 index, u16 value);
65
66/*--------------------------------------------------------------------------
67  Write 64-bit data to the fast serial bus registers.
68  Return 0 on success, -1 otherwise.
69  --------------------------------------------------------------------------*/
70static void w9968cf_write_fsb(struct sd *sd, u16* data)
71{
72	struct usb_device *udev = sd->gspca_dev.dev;
73	u16 value;
74	int ret;
75
76	if (sd->gspca_dev.usb_err < 0)
77		return;
78
79	value = *data++;
80	memcpy(sd->gspca_dev.usb_buf, data, 6);
81
82	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0,
83			      USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
84			      value, 0x06, sd->gspca_dev.usb_buf, 6, 500);
85	if (ret < 0) {
86		pr_err("Write FSB registers failed (%d)\n", ret);
87		sd->gspca_dev.usb_err = ret;
88	}
89}
90
91/*--------------------------------------------------------------------------
92  Write data to the serial bus control register.
93  Return 0 on success, a negative number otherwise.
94  --------------------------------------------------------------------------*/
95static void w9968cf_write_sb(struct sd *sd, u16 value)
96{
97	int ret;
98
99	if (sd->gspca_dev.usb_err < 0)
100		return;
101
102	/* We don't use reg_w here, as that would cause all writes when
103	   bitbanging i2c to be logged, making the logs impossible to read */
104	ret = usb_control_msg(sd->gspca_dev.dev,
105		usb_sndctrlpipe(sd->gspca_dev.dev, 0),
106		0,
107		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
108		value, 0x01, NULL, 0, 500);
109
110	udelay(W9968CF_I2C_BUS_DELAY);
111
112	if (ret < 0) {
113		pr_err("Write SB reg [01] %04x failed\n", value);
114		sd->gspca_dev.usb_err = ret;
115	}
116}
117
118/*--------------------------------------------------------------------------
119  Read data from the serial bus control register.
120  Return 0 on success, a negative number otherwise.
121  --------------------------------------------------------------------------*/
122static int w9968cf_read_sb(struct sd *sd)
123{
124	int ret;
125
126	if (sd->gspca_dev.usb_err < 0)
127		return -1;
128
129	/* We don't use reg_r here, as the w9968cf is special and has 16
130	   bit registers instead of 8 bit */
131	ret = usb_control_msg(sd->gspca_dev.dev,
132			usb_rcvctrlpipe(sd->gspca_dev.dev, 0),
133			1,
134			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
135			0, 0x01, sd->gspca_dev.usb_buf, 2, 500);
136	if (ret >= 0) {
137		ret = sd->gspca_dev.usb_buf[0] |
138		      (sd->gspca_dev.usb_buf[1] << 8);
139	} else {
140		pr_err("Read SB reg [01] failed\n");
141		sd->gspca_dev.usb_err = ret;
142	}
143
144	udelay(W9968CF_I2C_BUS_DELAY);
145
146	return ret;
147}
148
149/*--------------------------------------------------------------------------
150  Upload quantization tables for the JPEG compression.
151  This function is called by w9968cf_start_transfer().
152  Return 0 on success, a negative number otherwise.
153  --------------------------------------------------------------------------*/
154static void w9968cf_upload_quantizationtables(struct sd *sd)
155{
156	u16 a, b;
157	int i, j;
158
159	reg_w(sd, 0x39, 0x0010); /* JPEG clock enable */
160
161	for (i = 0, j = 0; i < 32; i++, j += 2) {
162		a = Y_QUANTABLE[j] | ((unsigned)(Y_QUANTABLE[j + 1]) << 8);
163		b = UV_QUANTABLE[j] | ((unsigned)(UV_QUANTABLE[j + 1]) << 8);
164		reg_w(sd, 0x40 + i, a);
165		reg_w(sd, 0x60 + i, b);
166	}
167	reg_w(sd, 0x39, 0x0012); /* JPEG encoder enable */
168}
169
170/****************************************************************************
171 * Low-level I2C I/O functions.                                             *
172 * The adapter supports the following I2C transfer functions:               *
173 * i2c_adap_fastwrite_byte_data() (at 400 kHz bit frequency only)           *
174 * i2c_adap_read_byte_data()                                                *
175 * i2c_adap_read_byte()                                                     *
176 ****************************************************************************/
177
178static void w9968cf_smbus_start(struct sd *sd)
179{
180	w9968cf_write_sb(sd, 0x0011); /* SDE=1, SDA=0, SCL=1 */
181	w9968cf_write_sb(sd, 0x0010); /* SDE=1, SDA=0, SCL=0 */
182}
183
184static void w9968cf_smbus_stop(struct sd *sd)
185{
186	w9968cf_write_sb(sd, 0x0010); /* SDE=1, SDA=0, SCL=0 */
187	w9968cf_write_sb(sd, 0x0011); /* SDE=1, SDA=0, SCL=1 */
188	w9968cf_write_sb(sd, 0x0013); /* SDE=1, SDA=1, SCL=1 */
189}
190
191static void w9968cf_smbus_write_byte(struct sd *sd, u8 v)
192{
193	u8 bit;
194	int sda;
195
196	for (bit = 0 ; bit < 8 ; bit++) {
197		sda = (v & 0x80) ? 2 : 0;
198		v <<= 1;
199		/* SDE=1, SDA=sda, SCL=0 */
200		w9968cf_write_sb(sd, 0x10 | sda);
201		/* SDE=1, SDA=sda, SCL=1 */
202		w9968cf_write_sb(sd, 0x11 | sda);
203		/* SDE=1, SDA=sda, SCL=0 */
204		w9968cf_write_sb(sd, 0x10 | sda);
205	}
206}
207
208static void w9968cf_smbus_read_byte(struct sd *sd, u8 *v)
209{
210	u8 bit;
211
212	/* No need to ensure SDA is high as we are always called after
213	   read_ack which ends with SDA high */
214	*v = 0;
215	for (bit = 0 ; bit < 8 ; bit++) {
216		*v <<= 1;
217		/* SDE=1, SDA=1, SCL=1 */
218		w9968cf_write_sb(sd, 0x0013);
219		*v |= (w9968cf_read_sb(sd) & 0x0008) ? 1 : 0;
220		/* SDE=1, SDA=1, SCL=0 */
221		w9968cf_write_sb(sd, 0x0012);
222	}
223}
224
225static void w9968cf_smbus_write_nack(struct sd *sd)
226{
227	/* No need to ensure SDA is high as we are always called after
228	   read_byte which ends with SDA high */
229	w9968cf_write_sb(sd, 0x0013); /* SDE=1, SDA=1, SCL=1 */
230	w9968cf_write_sb(sd, 0x0012); /* SDE=1, SDA=1, SCL=0 */
231}
232
233static void w9968cf_smbus_read_ack(struct sd *sd)
234{
235	struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
236	int sda;
237
238	/* Ensure SDA is high before raising clock to avoid a spurious stop */
239	w9968cf_write_sb(sd, 0x0012); /* SDE=1, SDA=1, SCL=0 */
240	w9968cf_write_sb(sd, 0x0013); /* SDE=1, SDA=1, SCL=1 */
241	sda = w9968cf_read_sb(sd);
242	w9968cf_write_sb(sd, 0x0012); /* SDE=1, SDA=1, SCL=0 */
243	if (sda >= 0 && (sda & 0x08)) {
244		PDEBUG(D_USBI, "Did not receive i2c ACK");
245		sd->gspca_dev.usb_err = -EIO;
246	}
247}
248
249/* SMBus protocol: S Addr Wr [A] Subaddr [A] Value [A] P */
250static void w9968cf_i2c_w(struct sd *sd, u8 reg, u8 value)
251{
252	struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
253	u16* data = (u16 *)sd->gspca_dev.usb_buf;
254
255	data[0] = 0x082f | ((sd->sensor_addr & 0x80) ? 0x1500 : 0x0);
256	data[0] |= (sd->sensor_addr & 0x40) ? 0x4000 : 0x0;
257	data[1] = 0x2082 | ((sd->sensor_addr & 0x40) ? 0x0005 : 0x0);
258	data[1] |= (sd->sensor_addr & 0x20) ? 0x0150 : 0x0;
259	data[1] |= (sd->sensor_addr & 0x10) ? 0x5400 : 0x0;
260	data[2] = 0x8208 | ((sd->sensor_addr & 0x08) ? 0x0015 : 0x0);
261	data[2] |= (sd->sensor_addr & 0x04) ? 0x0540 : 0x0;
262	data[2] |= (sd->sensor_addr & 0x02) ? 0x5000 : 0x0;
263	data[3] = 0x1d20 | ((sd->sensor_addr & 0x02) ? 0x0001 : 0x0);
264	data[3] |= (sd->sensor_addr & 0x01) ? 0x0054 : 0x0;
265
266	w9968cf_write_fsb(sd, data);
267
268	data[0] = 0x8208 | ((reg & 0x80) ? 0x0015 : 0x0);
269	data[0] |= (reg & 0x40) ? 0x0540 : 0x0;
270	data[0] |= (reg & 0x20) ? 0x5000 : 0x0;
271	data[1] = 0x0820 | ((reg & 0x20) ? 0x0001 : 0x0);
272	data[1] |= (reg & 0x10) ? 0x0054 : 0x0;
273	data[1] |= (reg & 0x08) ? 0x1500 : 0x0;
274	data[1] |= (reg & 0x04) ? 0x4000 : 0x0;
275	data[2] = 0x2082 | ((reg & 0x04) ? 0x0005 : 0x0);
276	data[2] |= (reg & 0x02) ? 0x0150 : 0x0;
277	data[2] |= (reg & 0x01) ? 0x5400 : 0x0;
278	data[3] = 0x001d;
279
280	w9968cf_write_fsb(sd, data);
281
282	data[0] = 0x8208 | ((value & 0x80) ? 0x0015 : 0x0);
283	data[0] |= (value & 0x40) ? 0x0540 : 0x0;
284	data[0] |= (value & 0x20) ? 0x5000 : 0x0;
285	data[1] = 0x0820 | ((value & 0x20) ? 0x0001 : 0x0);
286	data[1] |= (value & 0x10) ? 0x0054 : 0x0;
287	data[1] |= (value & 0x08) ? 0x1500 : 0x0;
288	data[1] |= (value & 0x04) ? 0x4000 : 0x0;
289	data[2] = 0x2082 | ((value & 0x04) ? 0x0005 : 0x0);
290	data[2] |= (value & 0x02) ? 0x0150 : 0x0;
291	data[2] |= (value & 0x01) ? 0x5400 : 0x0;
292	data[3] = 0xfe1d;
293
294	w9968cf_write_fsb(sd, data);
295
296	PDEBUG(D_USBO, "i2c 0x%02x -> [0x%02x]", value, reg);
297}
298
299/* SMBus protocol: S Addr Wr [A] Subaddr [A] P S Addr+1 Rd [A] [Value] NA P */
300static int w9968cf_i2c_r(struct sd *sd, u8 reg)
301{
302	struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
303	int ret = 0;
304	u8 value;
305
306	/* Fast serial bus data control disable */
307	w9968cf_write_sb(sd, 0x0013); /* don't change ! */
308
309	w9968cf_smbus_start(sd);
310	w9968cf_smbus_write_byte(sd, sd->sensor_addr);
311	w9968cf_smbus_read_ack(sd);
312	w9968cf_smbus_write_byte(sd, reg);
313	w9968cf_smbus_read_ack(sd);
314	w9968cf_smbus_stop(sd);
315	w9968cf_smbus_start(sd);
316	w9968cf_smbus_write_byte(sd, sd->sensor_addr + 1);
317	w9968cf_smbus_read_ack(sd);
318	w9968cf_smbus_read_byte(sd, &value);
319	/* signal we don't want to read anymore, the v4l1 driver used to
320	   send an ack here which is very wrong! (and then fixed
321	   the issues this gave by retrying reads) */
322	w9968cf_smbus_write_nack(sd);
323	w9968cf_smbus_stop(sd);
324
325	/* Fast serial bus data control re-enable */
326	w9968cf_write_sb(sd, 0x0030);
327
328	if (sd->gspca_dev.usb_err >= 0) {
329		ret = value;
330		PDEBUG(D_USBI, "i2c [0x%02X] -> 0x%02X", reg, value);
331	} else
332		PERR("i2c read [0x%02x] failed", reg);
333
334	return ret;
335}
336
337/*--------------------------------------------------------------------------
338  Turn on the LED on some webcams. A beep should be heard too.
339  Return 0 on success, a negative number otherwise.
340  --------------------------------------------------------------------------*/
341static void w9968cf_configure(struct sd *sd)
342{
343	reg_w(sd, 0x00, 0xff00); /* power-down */
344	reg_w(sd, 0x00, 0xbf17); /* reset everything */
345	reg_w(sd, 0x00, 0xbf10); /* normal operation */
346	reg_w(sd, 0x01, 0x0010); /* serial bus, SDS high */
347	reg_w(sd, 0x01, 0x0000); /* serial bus, SDS low */
348	reg_w(sd, 0x01, 0x0010); /* ..high 'beep-beep' */
349	reg_w(sd, 0x01, 0x0030); /* Set sda scl to FSB mode */
350
351	sd->stopped = 1;
352}
353
354static void w9968cf_init(struct sd *sd)
355{
356	unsigned long hw_bufsize = sd->sif ? (352 * 288 * 2) : (640 * 480 * 2),
357		      y0 = 0x0000,
358		      u0 = y0 + hw_bufsize / 2,
359		      v0 = u0 + hw_bufsize / 4,
360		      y1 = v0 + hw_bufsize / 4,
361		      u1 = y1 + hw_bufsize / 2,
362		      v1 = u1 + hw_bufsize / 4;
363
364	reg_w(sd, 0x00, 0xff00); /* power off */
365	reg_w(sd, 0x00, 0xbf10); /* power on */
366
367	reg_w(sd, 0x03, 0x405d); /* DRAM timings */
368	reg_w(sd, 0x04, 0x0030); /* SDRAM timings */
369
370	reg_w(sd, 0x20, y0 & 0xffff); /* Y buf.0, low */
371	reg_w(sd, 0x21, y0 >> 16);    /* Y buf.0, high */
372	reg_w(sd, 0x24, u0 & 0xffff); /* U buf.0, low */
373	reg_w(sd, 0x25, u0 >> 16);    /* U buf.0, high */
374	reg_w(sd, 0x28, v0 & 0xffff); /* V buf.0, low */
375	reg_w(sd, 0x29, v0 >> 16);    /* V buf.0, high */
376
377	reg_w(sd, 0x22, y1 & 0xffff); /* Y buf.1, low */
378	reg_w(sd, 0x23, y1 >> 16);    /* Y buf.1, high */
379	reg_w(sd, 0x26, u1 & 0xffff); /* U buf.1, low */
380	reg_w(sd, 0x27, u1 >> 16);    /* U buf.1, high */
381	reg_w(sd, 0x2a, v1 & 0xffff); /* V buf.1, low */
382	reg_w(sd, 0x2b, v1 >> 16);    /* V buf.1, high */
383
384	reg_w(sd, 0x32, y1 & 0xffff); /* JPEG buf 0 low */
385	reg_w(sd, 0x33, y1 >> 16);    /* JPEG buf 0 high */
386
387	reg_w(sd, 0x34, y1 & 0xffff); /* JPEG buf 1 low */
388	reg_w(sd, 0x35, y1 >> 16);    /* JPEG bug 1 high */
389
390	reg_w(sd, 0x36, 0x0000);/* JPEG restart interval */
391	reg_w(sd, 0x37, 0x0804);/*JPEG VLE FIFO threshold*/
392	reg_w(sd, 0x38, 0x0000);/* disable hw up-scaling */
393	reg_w(sd, 0x3f, 0x0000); /* JPEG/MCTL test data */
394}
395
396static void w9968cf_set_crop_window(struct sd *sd)
397{
398	int start_cropx, start_cropy,  x, y, fw, fh, cw, ch,
399	    max_width, max_height;
400
401	if (sd->sif) {
402		max_width  = 352;
403		max_height = 288;
404	} else {
405		max_width  = 640;
406		max_height = 480;
407	}
408
409	if (sd->sensor == SEN_OV7620) {
410		/*
411		 * Sigh, this is dependend on the clock / framerate changes
412		 * made by the frequency control, sick.
413		 *
414		 * Note we cannot use v4l2_ctrl_g_ctrl here, as we get called
415		 * from ov519.c:setfreq() with the ctrl lock held!
416		 */
417		if (sd->freq->val == 1) {
418			start_cropx = 277;
419			start_cropy = 37;
420		} else {
421			start_cropx = 105;
422			start_cropy = 37;
423		}
424	} else {
425		start_cropx = 320;
426		start_cropy = 35;
427	}
428
429	/* Work around to avoid FP arithmetics */
430	#define SC(x) ((x) << 10)
431
432	/* Scaling factors */
433	fw = SC(sd->gspca_dev.pixfmt.width) / max_width;
434	fh = SC(sd->gspca_dev.pixfmt.height) / max_height;
435
436	cw = (fw >= fh) ? max_width : SC(sd->gspca_dev.pixfmt.width) / fh;
437	ch = (fw >= fh) ? SC(sd->gspca_dev.pixfmt.height) / fw : max_height;
438
439	sd->sensor_width = max_width;
440	sd->sensor_height = max_height;
441
442	x = (max_width - cw) / 2;
443	y = (max_height - ch) / 2;
444
445	reg_w(sd, 0x10, start_cropx + x);
446	reg_w(sd, 0x11, start_cropy + y);
447	reg_w(sd, 0x12, start_cropx + x + cw);
448	reg_w(sd, 0x13, start_cropy + y + ch);
449}
450
451static void w9968cf_mode_init_regs(struct sd *sd)
452{
453	int val, vs_polarity, hs_polarity;
454
455	w9968cf_set_crop_window(sd);
456
457	reg_w(sd, 0x14, sd->gspca_dev.pixfmt.width);
458	reg_w(sd, 0x15, sd->gspca_dev.pixfmt.height);
459
460	/* JPEG width & height */
461	reg_w(sd, 0x30, sd->gspca_dev.pixfmt.width);
462	reg_w(sd, 0x31, sd->gspca_dev.pixfmt.height);
463
464	/* Y & UV frame buffer strides (in WORD) */
465	if (w9968cf_vga_mode[sd->gspca_dev.curr_mode].pixelformat ==
466	    V4L2_PIX_FMT_JPEG) {
467		reg_w(sd, 0x2c, sd->gspca_dev.pixfmt.width / 2);
468		reg_w(sd, 0x2d, sd->gspca_dev.pixfmt.width / 4);
469	} else
470		reg_w(sd, 0x2c, sd->gspca_dev.pixfmt.width);
471
472	reg_w(sd, 0x00, 0xbf17); /* reset everything */
473	reg_w(sd, 0x00, 0xbf10); /* normal operation */
474
475	/* Transfer size in WORDS (for UYVY format only) */
476	val = sd->gspca_dev.pixfmt.width * sd->gspca_dev.pixfmt.height;
477	reg_w(sd, 0x3d, val & 0xffff); /* low bits */
478	reg_w(sd, 0x3e, val >> 16);    /* high bits */
479
480	if (w9968cf_vga_mode[sd->gspca_dev.curr_mode].pixelformat ==
481	    V4L2_PIX_FMT_JPEG) {
482		/* We may get called multiple times (usb isoc bw negotiat.) */
483		jpeg_define(sd->jpeg_hdr, sd->gspca_dev.pixfmt.height,
484			    sd->gspca_dev.pixfmt.width, 0x22); /* JPEG 420 */
485		jpeg_set_qual(sd->jpeg_hdr, v4l2_ctrl_g_ctrl(sd->jpegqual));
486		w9968cf_upload_quantizationtables(sd);
487		v4l2_ctrl_grab(sd->jpegqual, true);
488	}
489
490	/* Video Capture Control Register */
491	if (sd->sensor == SEN_OV7620) {
492		/* Seems to work around a bug in the image sensor */
493		vs_polarity = 1;
494		hs_polarity = 1;
495	} else {
496		vs_polarity = 1;
497		hs_polarity = 0;
498	}
499
500	val = (vs_polarity << 12) | (hs_polarity << 11);
501
502	/* NOTE: We may not have enough memory to do double buffering while
503	   doing compression (amount of memory differs per model cam).
504	   So we use the second image buffer also as jpeg stream buffer
505	   (see w9968cf_init), and disable double buffering. */
506	if (w9968cf_vga_mode[sd->gspca_dev.curr_mode].pixelformat ==
507	    V4L2_PIX_FMT_JPEG) {
508		/* val |= 0x0002; YUV422P */
509		val |= 0x0003; /* YUV420P */
510	} else
511		val |= 0x0080; /* Enable HW double buffering */
512
513	/* val |= 0x0020; enable clamping */
514	/* val |= 0x0008; enable (1-2-1) filter */
515	/* val |= 0x000c; enable (2-3-6-3-2) filter */
516
517	val |= 0x8000; /* capt. enable */
518
519	reg_w(sd, 0x16, val);
520
521	sd->gspca_dev.empty_packet = 0;
522}
523
524static void w9968cf_stop0(struct sd *sd)
525{
526	v4l2_ctrl_grab(sd->jpegqual, false);
527	reg_w(sd, 0x39, 0x0000); /* disable JPEG encoder */
528	reg_w(sd, 0x16, 0x0000); /* stop video capture */
529}
530
531/* The w9968cf docs say that a 0 sized packet means EOF (and also SOF
532   for the next frame). This seems to simply not be true when operating
533   in JPEG mode, in this case there may be empty packets within the
534   frame. So in JPEG mode use the JPEG SOI marker to detect SOF.
535
536   Note to make things even more interesting the w9968cf sends *PLANAR* jpeg,
537   to be precise it sends: SOI, SOF, DRI, SOS, Y-data, SOS, U-data, SOS,
538   V-data, EOI. */
539static void w9968cf_pkt_scan(struct gspca_dev *gspca_dev,
540			u8 *data,			/* isoc packet */
541			int len)			/* iso packet length */
542{
543	struct sd *sd = (struct sd *) gspca_dev;
544
545	if (w9968cf_vga_mode[gspca_dev->curr_mode].pixelformat ==
546	    V4L2_PIX_FMT_JPEG) {
547		if (len >= 2 &&
548		    data[0] == 0xff &&
549		    data[1] == 0xd8) {
550			gspca_frame_add(gspca_dev, LAST_PACKET,
551					NULL, 0);
552			gspca_frame_add(gspca_dev, FIRST_PACKET,
553					sd->jpeg_hdr, JPEG_HDR_SZ);
554			/* Strip the ff d8, our own header (which adds
555			   huffman and quantization tables) already has this */
556			len -= 2;
557			data += 2;
558		}
559	} else {
560		/* In UYVY mode an empty packet signals EOF */
561		if (gspca_dev->empty_packet) {
562			gspca_frame_add(gspca_dev, LAST_PACKET,
563						NULL, 0);
564			gspca_frame_add(gspca_dev, FIRST_PACKET,
565					NULL, 0);
566			gspca_dev->empty_packet = 0;
567		}
568	}
569	gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
570}
571